The BOJ's latest monetary policy meeting led to widespread disappointment. That’s unfair. The changes announced were not showy — but they were essential for the country’s bond investors.

Before the Bank of Japan’s monetary policy board met on Friday, economists wondered quite how aggressive the central bank’s swashbuckling governor, Haruhiko Kuroda, would be. Would he push Japan further into negative interest rates Would he announce a big increase in the BOJ’s bond purchase programme Would he find some radical new measure, sending shockwaves through the currency and equity markets